<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script>
			var n=prompt("请输入一个数字");
			if(isNaN(n)){
				alert("无法整体转换成数字");
			}else{
				var k=parseInt(n);//NaN
				alert(k);
			}
			
		</script>
	</head>
	<body>
	</body>
</html>